/*******************************************************************************
 * Copyright 2009, 2010 Innovation Gate GmbH. All Rights Reserved.
 * 
 * This file is part of the OpenWGA server platform.
 * 
 * OpenWGA is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * In addition, a special exception is granted by the copyright holders
 * of OpenWGA called "OpenWGA plugin exception". You should have received
 * a copy of this exception along with OpenWGA in file COPYING.
 * If not, see <http://www.openwga.com/gpl-plugin-exception>.
 * 
 * OpenWGA is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with OpenWGA in file COPYING.
 * If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/

package de.innovationgate.wgpublisher.logserver;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.collections.Buffer;
import org.apache.log4j.WriterAppender;

import de.innovationgate.utils.LineBufferWriter;
import de.innovationgate.wgpublisher.WGACore;

public class AppLogTailHandler implements TailHandler {
    
    private WGACore _core;
    private LineBufferWriter _listWriter;
    private WriterAppender _appender;

    public AppLogTailHandler(WGACore core) {
        _core = core;
        _listWriter = new LineBufferWriter();
        _appender = new WriterAppender(WGACore.LAYOUT_APPLOG, _listWriter);
        _core.getLog().addAppender(_appender);
    }

    public synchronized List refresh() throws IOException {
        
        List lines = new ArrayList();
        Buffer buffer = _listWriter.getBuffer();
        while (buffer.size() > 0) {
            lines.add(buffer.remove());
        }
        return lines;
        
    }
    
    public void shutdown() {
      _core.getLog().removeAppender(_appender);
    }

}
